It has long been known in the disposable absorbent bandage an that it is extremely desirable to construct absorptive devices, such as disposable diapers, sanitary napkins, incontinent briefs, and the like, presenting a dry cloth-like surface feel to the user's skin at any anticipated points of contact, e.g., topsheets and/or backsheets.
While woven and nonwoven fibrous webs are often employed for this purpose because of their pleasant surface feel, polymeric webs have been shown to exhibit more desirable fluid transport and fluid restraining characteristics in many circumstances.
U.S. Pat. No. 4,629,643 issued to Curro et al. on Dec. 16, 1986 discloses a microapertured polymeric web which exhibits a soft and silky tactile impression on at least one surface thereof. The silky feeling surface of the web exhibits a pattern of discrete volcano-like surface aberrations which are not readily discernible to the normal naked eye when the perpendicular distance between the web and the observer's eye is at least about 12 inches. The density of the surface aberrations being at least about 3,600 per square inch, and the center-to-center distance between adjacent surface aberrations does not exceed about 25 mils. Each surface aberration has its amplitude oriented substantially perpendicular to the surface in which said surface aberration originates and exhibits a maximum cross-sectional dimension not exceeding about 20 mils as measured perpendicular to its amplitude. The end of each surface aberration includes at least one microaperture substantially coincidental with its point of maximum amplitude. The microaperture exhibits a multiplicity of thin, irregularly shaped petals about its periphery. The microaperture creates a discontinuity which reduces the resistance to compression and shear of each surface aberration as well as the degree of contact with the observer's skin, whereby the tactile impression of the web is perceived as generally soft and silky.
While the microapertured web of Curro et al. is particularly well suited for use as a backsheet and/or topsheet on a disposable absorbent article, the microapertured web may still give the impression of a plastic web as the portion of the web of film between adjacent microapertures is substantially planar.
Accordingly, it is an object of the present invention to provide a microapertured plastic web which exhibits a soft and silky tactile impression and which exhibits a cloth-like or nonplastic visual appearance.
As used herein the term "microapertured", when used to describe plastic webs, ribbons and films of the present invention, refers to webs, ribbons and films which have been caused to conform to the surface of a three-dimensional forming structure so that both surfaces thereof exhibits a three-dimensional pattern of apertures corresponding to the cross-section of the forming structure, the apertures comprising the pattern not being individually discernible to the normal naked eye when the perpendicular distance between the viewer's eye and the plane of the web is about 12 inches. As used herein the term "microembossed", when used to describe plastic webs, ribbons and films of the present invention, refers to webs, ribbons and films which have been caused to conform to the surface of a three-dimensional forming so that both surfaces thereof exhibit a three-dimensional pattern of surface aberrations corresponding to the cross-section of the forming structure, the surface aberrations comprising the pattern not being individually discernible to the normal naked eye when the perpendicular distance between the viewer's eye and the plane of the web is about 12 inches.